JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2022
·
IF 4.383
Baogang Su,Qi Zhang,Linjun Shao,Shujing Zhou,Jinjing Li,Yijun Du,Chenze Qi
Heterogeneous palladium catalysts play an important role in the synthetic organic chemistry. Palladium species have been adsorbed on the surface of solid matrices or embedded inside solid matrices to prepare recyclable heterogeneous catalysts. Due to the different surrounding environment, these two type palladium species had different electronic properties and catalytic performances. In this study, we fabricated three series of chitosan composite nanofibers with adsorbed and embedded palladium species. Their fiber morphologies and chemical structures were characterized by SEM and FT-IR, respectively. Positron annihilation lifetime spectra (PALS) showed that the intensities (I 3 ) of o -Ps annihilations were all linearly decreased with the increase of palladium contents in the chitosan composite nanofibers. Moreover, compared with the palladium adsorbed chitosan composite nanofibers, the palladium embedded chitosan composite nanofibers had stronger o -Ps annihilation ability, which could be ascribed to the stronger electron donating property of embedded palladium species and higher crosslinking of chitosan molecules by embedded palladium species. At last, the I 3 values were successfully correlated with the rate constants of chitosan supported palladium composite nanofibers catalyzed Suzuki reactions of iodobenzene with phenylboric acid. Therefore, we have developed a facile method to distinguish the adsorbed and embedded palladium species by PALS, which can be further related with their catalytic performance.
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Linfeng Chen,Lu Li,Dong Wu,Xike Tian,Dasha Xia,Liqiang Lu,Chao Yang,Yulun Nie
Herein, a small molecule based multi-channel fluorescent sensor array ( SA ) for accurate discrimination and sensitive quantitation of multiple heavy metal ions was developed, with its detection mechanism simulates an electronic tongue. The synergistic effects of the differentiated affinity of chelator for metal ions and multiple emission channels of sensors led to the diverse emission intensity change and wavelength switch, displaying obvious cross-reactivity and diversified signal output. Treated with linear discriminant analysis (LDA), this diversified multi-channel output allowed correct and high-resolution discrimination of 11 heavy metal ions at different concentration as well as multivariate mixture of hard-distinguish metal ions. Further titration experiment exhibited the regular arrangement of each metal ions in different extension directions at the range of 0–20 μM in 3D LDA plot, endowing SA array with the ability to identify and quantify each heavy metal ion. The feasibility of the SA array was also verified by the accurate detection of a large number of actual water samples. This strategy enables simple, efficient, sensitive identification and quantification of multiple metal ions in real water, demonstrating its potential for simplification of water quality analysis process.
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DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 12
·125101
·
IF 1.449
Kai Huang,Lin Lin Guo,Dong Fang Wu
Different from the traditional aldimine condensation reaction, N-containing ligand: pyridine-2-formaldehyde was selected as the source of aldehyde group, and NH2-MIL-53(Al) containing a large number of amino functional groups was took as the carrier, transition metal Cu2+ coordinated with N-containing ligand to prepare a new and more stable MOFs catalyst named Cu@Al-MIL-53-P21. The catalyst exhibited a cross-linked nanorod morphology. The effect of the morphology on the catalytic oxidation activity of styrene was studied, the results showed that the catalyst could not only promote the production of benzaldehyde, but also inhibit the production of benzoic acid and phenylacetaldehyde. In addition, the optimal reaction conditions and the reaction mechanism were also discussed in this paper.
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DOI
高影响因子
GREEN CHEMISTRY
·
2018
·Vol. 21
·期 3
·567-577
·
IF 8.586
Wenfeng Zhao,Xiaoping Chi,Hu Li,Jian He,Jingxuan Long,Yufei Xu,Song Yang
Catalytic fixation of CO2 to produce valuable fine chemicals is of great significance to develop a green and sustainable circulation of excessive carbon in the environment. Herein, a series of non-toxic, biodegradable and recyclable acetylcholine-carboxylate bio-ionic liquids with different cations and anions were simply synthesized for producing formamides and methylamines using atmospheric CO2 as a carbon source, and phenylsilane as a hydrogen donor. The selectivity toward products was tuned by altering the reaction temperature under solvent or solvent-free conditions. N-Methylamines (ca. 96% yield) were obtained in acetonitrile at 50 °C, while N-formamides (ca. 99% yield) were attained without a solvent at 30 °C. The established bio-ionic liquid catalytic system found a wide range of applicability in substrates and possessed a high potentiality in scale-up to gram-grade production. The developed catalytic system was fairly stable, which could be easily reused without an apparent loss of reactivity, possibly due to the strong electrostatic interactions between the cation and anion. The combination of experimental and computational results explicitly elucidated the reaction mechanism: PhSiH3 activated by a bio-IL was favorable for the formation of silyl formate from hydrosilylation of CO2, followed by a reaction with an amine to give an N-formamide, while an N-methylamine was formed by further hydrosilylation of the N-formamide.
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DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-10
·
IF 5.578
Tong Mingquan,Zhang Daliang,Fan Weibin,Xu Jun,Zhu Liangkui,Guo Wen,Yan Wenfu,Yu Jihong,Qiu Shilun,Wang Jianguo,Deng Feng,Xu Ruren
Chiral zeolitic materials with intrinsically chiral frameworks are highly desired because they can combine both shape selectivity and enantioselectivity. In the field of zeolite, the synthesis of chiral polymorph A of zeolite Beta or chiral polymorph A-enriched zeolite Beta is one of the biggest challenges. We demonstrate here a generalized extremely concentrated fluoride route for the synthesis of chiral polymorph A-enriched zeolite Beta in the presence of five achiral organic structure-directing agents. The polymorph A-enriched Ti-Beta shows a higher enantioselectivity for the asymmetric epoxidation of alkenes than the normal Ti-Beta.
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）